Role of orexin-A in doxapram-induced promotion of emergence from general anesthesia / 中华麻醉学杂志

Objective To investigate the role of orexin-A in doxapram-induced promotion of emergence from general anesthesia in patients.Methods Forty-four patients of both sexes,aged 18-60 yr,with body mass index of 21-25 kg/m2,of American Society of Anesthesiology physical status Ⅰ or Ⅱ,scheduled for elective lumbar surgery under general anesthesia,were divided into 2 groups (n =22 each) using a random number table:control group and doxapram group.Anesthesia was induced by intravenously injecting propofol,sufentanil and cisatracurium.The patients were mechanically ventilated after tracheal intubation.Anesthesia was maintained by inhaling sevoflurane and target-controlled infusion of remifentanil.Sevoflurane inhalation and remifentanil infusion were stopped at the end of operation,oxygen flow rate was adjusted to 6 L/min,doxapram 0.5 mg/kg were intravenously injected at the same time in doxapram group,and the equal volume of normal saline was given in control group.The emergence time and extubation time were recorded.On admission to operating room (T0),at 1 h after anesthesia induction (T1) and 5 and 30 min after tracheal extubation (T2,3),arterial blood samples were collected for determination of blood glucose concentrations and plasma orexin-A concentrations (by radioimmunoassay).Results Compared with the baseline at T0,blood glucose concentrations were significantly decreased at T1 and increased at T3,and plasma orexin-A concentrations were increased at T2 in two groups (P ＜ 0.05).Compared with control group,the time to eye opening and extubation time were significantly shortened,plasma orexin-A concentrations were increased at T2 (P＜0.05),and no significant change was found in blood glucose concentrations at each time point in doxapram group (P＞0.05).Conclusion The mechanism by which doxapram promotes emergence from general anesthesia may be related to increasing plasma orexin-A concentrations in patients.

Pharmacokinetics of doxapram injection in Chinese Han, Mongolian, Korean, Uigur and Hui healthy subjects / 中国药理学通报

Aim To investigate and compare the phar-macokinetics of doxapram injection in healthy subjects of different Chinese nationalities including Han, Mon-golian, Korean, Hui and Uigur, and the influence of gender,in order to provide instruction and help for the usage of doxapram for both clinic and remedy of battle wound. Methods An HPLC-UV method was used to determine the plasma concentration of doxapram. Fifty healthy subjects ( five males and five females of each nationality) were recruited for the study. A single dose of 50 mg doxapram was administered intravenously to the healthy subjects, and blood samples were collected at various predetermined time points. The pharmacoki-netic parameters were calculated by DAS software and were compared by SPSS 13. 0 software, in order to as-sess the influence of nationality or gender on pharmaco-kinetics of doxapram. Results The results indicated that the pharmacokinetic profile of doxapram in vivo could be described as two-compartment model. The main pharmacokinetic parameters for Han, Mongolian, Korean, Hui and Uygur were as follows: Cl ( 0. 25 ± 0. 11 ) , ( 0. 33 ± 0. 11 ) , ( 0. 27 ± 0. 07 ) , ( 0. 26 ± 0. 06) and (0. 39 ± 0. 25) L·h-1 ·kg-1 , while Cmax (1. 55 ± 0. 52 ) , ( 1. 02 ± 0. 30 ) , ( 1. 31 ± 0. 47 ) , (1. 48 ± 0. 46 ) and ( 0. 99 ± 0. 35 ) mg · L-1 . The AUC0-12. 5 , AUC0-∞ and Cmax of Chinese Han were sig-nificantly higher than those of Uigur and Mongolian ( P0. 05 ) . There were statistically significant differences in Vc , Vd and CL between young males and females ( P < 0. 05 ) . Conclusion The large inter-individual variation in the main pharmacoki-netics suggests the dosage of doxapram should be ad-justed for different nationalities for both clinic and rem-edy of battle wound.

Population pharmacokinetics of doxapram in five different Chinese ethnic groups / 中国药学杂志

OBJECTIVE: To construct a population pharmacokinetic (PPK) model of doxapram in five different ethnic groups including Han, Mongolian, Korean, Hui and Uigur by NONMEM. METHODS: Fifty healthy volunteers were given a single dose of 50 mg doxapram intravenously. Blood samples were collected and determined by HPLC with a UV detector. Population pharmacokinetic model was constructed by NONMEM software. The influences of fixed-effect factors on the PK parameters were investigated. RESULTS: The following population parameters were estimated with a three-compartment model: CL1 of 17.8 L · h-1, CL2 of 10.5 L · h-1, CL3 of 85.2 L · h-1, V1 of 17.4 L, V2 of 62.6 L, and V3 of 16.8 L. Ethnic group has a significant effect on V2, CL3 and CL1, while gender has a significant effect on CL2. CONCLUSION: The final PPK model of doxapram established by NONMEM is robust and reliable. It may be beneficial for the clinical use of doxapram. Copyright 2013 by the Chinese Pharmaceutical Association.

Effect of doxapram on inhibition of medullary respiratory center excitability by sevoflurane in rats / 中华麻醉学杂志

Objective To investigate the effect of doxapram on inhibition of medullary respiratory center excitability by sevoflurane in rats.Methods Neonatal Sprague-Dawley rats of both sexes,aged 1-4 days,were used in this study.Isolated medulla oblongata-spinal cord specimens were made according to the method described by Suzue and perfused with the artificial cerebrospinal fluid saturated with 95％O2-5％CO2.The specimens were randomly divided into 3 groups ( n =9 each):control group (group C),sevoflurane group (group S) and sevoflurane + doxapram group (group S + D).Respiratory rhythmical discharge activity of the hypoglossal nerve rootlets was recorded using suction electrode.After 10 min of equilibration,the specimens were perfused with the artificial cerebrospinal fluid,5％ sevoflurane and the mixture of 5％ sevoflurane and 5 μmol/L doxapram for 10 min in groups C,S,and S + D respectively.The respiratory cycle,inspiratory time and integral amplitude of inspiratory discharge were recorded.Results Compared with group C,the respiratory cycle was significantly prolonged,the inspiratory time was significantly shortened,and the integral amplitude of inspiratory discharge was significantly decreased in group S (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group S + D (P ＞ 0.05).Compared with group S,the respiratory cycle was significantly shortened,the inspiratory time was significantly prolonged,the integral amplitude of inspiratory discharge was significantly increased in group S + D ( P ＜ 0.05).Conclusion Doxapram antagonizes sevoflurane-induced inhibition of excitability of medullary respiratory center in rats.

Effect of daxapram on recovery following total intravenous anesthesia with propofol and remifentanil / 대한마취과학회지

BACKGROUND: The aim of this study was to investigate the effect of doxapram on recovery following propofol-remifentanil anesthesia. METHODS: Forty patients scheduled for gastrectomy were randomly allocated to receive either doxapram 1 mg/kg or normal saline at the end of surgery under propofol-remifentanil anesthesia. Clinical recovery from anesthesia was assessed by times to spontaneous breathing, eye opening on verbal command, extubation, and discharge from the postanesthetic care unit (PACU). Bispectral index (BIS) values, blood pressure, and heart rate were recorded every 2 min for 16 min after the administration of doxapram or saline. The incidences of side effects were checked in the recovery room. RESULTS: Spontaneous breathing was recovered after 6.2 +/- 1.1 minutes in the Doxapram group versus 9.2 +/- 1.8 minutes in the normal saline group (P < 0.001). Times to eye and extubation were also shorter in the Doxapram patients than in the normal saline patients (6.9 +/- 1.0 and 8.1 +/- 1.7 min versus 10.4 +/- 2.0 and 12.0 +/- 2.6 min, respectively) (P < 0.001). However, the times to PACU discharge were not different between the two groups (46.9 +/- 4.9 min versus 47.0 +/- 6.0 min, respectively). The patients in the Doxapram group showed higher mean BIS values compared with the normal saline group during emergence, but there were no differences in arterial blood pressure, heart rate and incidences of side effects between the two groups. CONCLUSIONS: Doxapram 1 mg/kg hastens early recovery from TIVA with propofol and remifentanil, and this emergence effect correlates with higher BIS values. Doxapram, however, does not affect the discharge time from the PACU and incidences of side effects.

Effect of daxapram on recovery following total intravenous anesthesia with propofol and remifentanil / 대한마취과학회지

BACKGROUND: The aim of this study was to investigate the effect of doxapram on recovery following propofol-remifentanil anesthesia. METHODS: Forty patients scheduled for gastrectomy were randomly allocated to receive either doxapram 1 mg/kg or normal saline at the end of surgery under propofol-remifentanil anesthesia. Clinical recovery from anesthesia was assessed by times to spontaneous breathing, eye opening on verbal command, extubation, and discharge from the postanesthetic care unit (PACU). Bispectral index (BIS) values, blood pressure, and heart rate were recorded every 2 min for 16 min after the administration of doxapram or saline. The incidences of side effects were checked in the recovery room. RESULTS: Spontaneous breathing was recovered after 6.2 +/- 1.1 minutes in the Doxapram group versus 9.2 +/- 1.8 minutes in the normal saline group (P < 0.001). Times to eye and extubation were also shorter in the Doxapram patients than in the normal saline patients (6.9 +/- 1.0 and 8.1 +/- 1.7 min versus 10.4 +/- 2.0 and 12.0 +/- 2.6 min, respectively) (P < 0.001). However, the times to PACU discharge were not different between the two groups (46.9 +/- 4.9 min versus 47.0 +/- 6.0 min, respectively). The patients in the Doxapram group showed higher mean BIS values compared with the normal saline group during emergence, but there were no differences in arterial blood pressure, heart rate and incidences of side effects between the two groups. CONCLUSIONS: Doxapram 1 mg/kg hastens early recovery from TIVA with propofol and remifentanil, and this emergence effect correlates with higher BIS values. Doxapram, however, does not affect the discharge time from the PACU and incidences of side effects.

The Effect of Doxapram Hydrochloride on Bispectral (BIS) Index and Recovery from Desflurane Inhalational Anesthesia / 대한마취과학회지

BACKGROUND: Doxapram hydrochloride is a respiratory stimulant that produces arousal effects in patients under anesthesia. We investigated the effects of doxapram on the recovery time and BIS index of patients administered desflurane inhalational anesthesia. METHODS: 40 patients who underwent general anesthesia using desflurane that had an ASA physical status of I or II received either 1 mg/kg of doxapram hydrochloride (doxapram group, n = 20) or normal saline (control group, n = 20) IV at end of surgery. Anesthetic recovery after the injection of doxapram was then determined based on the time to eye opening in response to verbal command, hand squeezing on command, time to extubation, and Aldrete recovery score. BIS index, systolic blood pressure, tidal volume and heart rate were recorded every minute for up to thirteen minutes. RESULTS: The doxapram group showed significantly shorter times to emergence based on eye opening in response verbal command (sec) (409 +/- 114 vs 320 +/- 116), hand squeezing on command (sec) (458 +/- 119 vs 351 +/- 114) and extubation (sec) (491 +/- 103 vs 418 +/- 79) compared to control group. The BIS score was not significantly different between the two groups. CONCLUSIONS: The Bis index was not significant higher in the doxapram group, with the exception of the measurement recorded at 2 minutes, however the recovery time from desflurane inhalational anesthesia was faster in the doxapram group than the control group.

The Effect of Doxapram Hydrochloride on the Ventilation Responses during Total Intravenous Anesthesia by Laryngeal Mask Airway / 대한마취과학회지

BACKGROUND: Intravenous anesthetics causes depression of ventilatory response to hypercapnea. Doxapram stimulates ventilation via peripheral and central chemoreceptors. This study was aimed to evaluate the effect of doxapram on ventilation during total intravenous anesthesia (TIVA). METHODS: 60 patients undergoing operation under spontaneous ventilation via laryngeal mask airwaywere randomly divided into 3 groups: Control group received 5% dextrous infusion, D-2 group received doxapram injection of 1 mg/kg followed by continuous infusion of 2 mg/kg/hr, and D-4 group received doxapram injection of 2 mg/kg followed by continuous infusion of 4 mg/kg/hr. Anesthesia was induced and maintained with propofol and remifentanil. Respiratory rate, tidal volume (VT) and arterial carbon dioxide tension (PaCO2) were measured before and 15 min after induction of anesthesia, 0(15 min after start of operation), 1, 2, 3, 5, 15, 30, 45, and 60 min after start of doxapram infusion during TIVA. RESULTS: VT was significantly increased 1 min after start of doxapram infusion and returned to the value of pre-doxapram infusion immediately. In D-4 group, VT was significantly (P < 0.05) increased again 5 min after doxapram infusion compared with the value of pre-doxapram infusion and control group. PaCO2 was decreased 1 min after start of doxapram infusion and then increased again 2 min after doxapram infusion. In D-4 group, the degree of increase of PaCO2 was significantly (P < 0.05) less than those of D-2 group. CONCLUSIONS: Doxapram injection of 2 mg/kg followed by continuous infusion of 4 mg/kg/hr improved the depression of ventilatory response during TIVA.

The Effect of Doxapram Hydrochloride on the Ventilation Responses during General Anesthesia with Volatile Agent by Laryngeal Mask Airway / 대한마취과학회지

BACKGROUND: Inhalation anesthetics are known to depress ventilatory response to hypercapnea. Doxapram hydrochloride is an analeptic drug, which acts as a respiratory stimulant via peripheral and central chemoreceptors. Although the postoperarive infusion of doxapram hydrochloride is known to attenuate the impairment of respiratory function, no report is available on respiratory response to this drug when applied during anesthesia. Therefore, the present study aimed to evaluate the effect of doxapram hydrochloride on respiratory function during anesthesia. METHODS: Sixty adult patients undergoing operation under spontaneous ventilation via laryngeal mask airway (LMA) were randomly categorized into 3 groups: A control group, which received 5% dextrous infusion, and two groups in which patients were infused with doxapram hydrochloride (0.5 or 2 mg/kg/hr) starting 15 min after commencement operation. Anesthesia was maintained with 1 MAC sevoflurane - 4 L N2O - 2 L O2 under spontaneous ventilation via LMA. Tidal volume (VT), respiratory rate (RR), and arterial carbon dioxide tension (PaCO2) were measured just before and 15 min after the induction of anesthesia, 15 min after the start of operation and 15, 30, 45, and 60 min after the start of doxapram hydrochloride infusion. RESULTS: Measured values of RR and PaCO2 were significantly elevated during anesthesia venous those measured just before the induction of anesthesia in all groups. VT was significantly reduced during anesthesia venous just before the induction of anesthesia in all groups. All percent changes of VT, RR and PaCO2 were similar all any measurement times, and showed no significant changes after the infusion of doxapram hydrochloride in all groups. CONCLUSIONS: Intraoperative doxapram hydrochloride treatment did not produce any significant respiratory response improvement during 1 MAC sevoflurane anesthesia.

Aminophylline or doxapram attenuates somnolence induced by postoperative intravenous analgesia with butorphanol / 中国临床药理学与治疗学

AIM: To study the altion of aminophylline or doxapram attenuate somnolence induced by postoperative intravenous analgesia with butorphanol.METHODS: One hundred and five adult patients were randomly divided into three groups under epidural blockade.0.01% butorphanol and 0.25% aminophylline analgesia-pump(groupⅠ,n=35),0.01% butorphanol and 0.15% doxapram analgesia-pump(groupⅡ,n=35),and 0.01% butorphanol analgesia-pump(group Ⅲ,n=35).Lethargy and analgesia effect were compared.RESULTS: The analgesia effects were satisfactory in the three groups after operation.conscious-sedation score(OAA/S)(at 8-24 h after operation)in groupⅢ was higher than those in groupⅠand Ⅱ(P

Anesthetic Experience of a Patient with Chronic Hypoventilation Syndrome: A case report / 대한마취과학회지

Alveolar hypoventilation exists by definition when arterial PaCO2 increases above the normal range of 37 to 42 mmHg, but in clinically important hypoventilation syndromes PaCO2 is generally in the range of 50 to 80 mmHg. The management of chronic hypoventilation must be individualized to the patient's particular disorder, circumstances and need. This is a case report of anesthetic management of a 63-year-old woman with central alveolar hypoventilation (CAH) secondary to cerebral infarction. For hip surgery epidural anesthesia with 0.5% bupivacaine was performed and doxapram was applied to maintain respiratory drive. The anesthetic experience with a brief review of literature is reported.

A Comparison of Effectiveness Correlated with Different Doses of Doxapram in the Treatment of Post-Anesthetic Shivering / 대한마취과학회지

BACKGROUND: Although post-anesthetic shivering may be a temporary phenomenon, it leads to detrimental effects such as increased oxygen consumption, hypoxemia, and difficulty in monitoring. Doxapram is a relatively new treatment for post-anesthetic shivering, but there have been few reports about its minimum effective dose. The purpose of this study was to find the minimum dose of doxapram which would show an antishivering effect. METHODS: Sixty patients who had developed post-anesthetic shivering were divided into six groups of ten patients each. The groups were divided into a control group, which received normal saline, and the doxapram groups, which received five different doses of doxapram (0.15, 0.2, 0.5, 1.0, 1.5 mg/kg). The antishivering effect (2, 5, 10, 15 minutes after treatment), blood pressure, heart rate and temperature were compared among the groups. RESULTS: There was a significant difference in antishivering effect between the group which received normal saline and the groups which received doxapram; however, there was no significant difference within the groups which received doxapram. CONCLUSIONS: We conclude that the dose of doxapram required to achieve an antishivering effect is much less than that currently in use.

A case of acute coma & respiratory arrest in Wernicke's encephalopathy caused by malnutrition / 대한내과학회지

We shoud give attention to Wernicke's encephalopathy as a cause of sudden coma & respiratory arrest in patients, who are not usually suspected to develop the disorder and empirical treatment with thiamine in cases of coma of unknown cause is recommended. Respiratory stimulants, doxapram & aminophylline have an effect in assisting ventilatory weaning in patient with central hypoventilation as a complication of acute Wernicke's encephalopathy No previous reports where doxapram had been used to assist weaning from mechanical ventilation in adults were noted. Nor has newly developed central hypoventilation been identified as an impediment to weaning in literature to date in Korea. We reported a rare case of Wernicke's encephalopathy caused by poor oral intake & inadequate nutritional suppliment after car accident, showing acute coma & respiratory arrest and treated adequately by thiamine replacement & mechanical ventilation with respiratory stimulant.

The Effects of Doxapram on the Pulmonary Function during Total Intravenous Anesthesia with Propofol According to Nalbuphine Pretreatment / 대한마취과학회지

BACKGROUND: Total intravenous anesthesia with propofol can cause respiratory depression and apnea especially during induction of anesthesia. To study the possibility of reversal of respiratory depression during anesthesia with propofol, pretreated with nabuphine or not, the respiratory effects of doxapram to spontaneously ventilating patients were investigated. METHODS: Patients were divided into 4 groups - saline-propofol-saline group (SPS), saline-propofol- doxapram group (SPD), nalbuphine-propofol-saline group (NPS), and nalbuphine-propofol-doxapram group (NPD). After saline or nalbuphine pretreatment, anesthesia was induced with propofol and then doxapram or saline was intravenously injected. Apneic time interval, blood pressure, heart rate, respiratory rate, minute ventilation, end tidal CO2 partial pressure and oxygen saturation were measured in every minutes during induction of anesthesia. Percent changes of each values were compared. RESULTS: There is no differences in apneic time intervals in each groups. The percent change of first minute ventilation in SPD group after doxapram injection unchanged significantly compared with those depressions of SPS, NPS and NPD group (p<0.05). Respiratory rates increased in SPD and SPS groups after laryngeal mask insertion. There is no differences in minute ventilation, respiratory rate and end-tidal CO2 concentration between nalbuphine pretreated groups regardless of doxapram injection. CONCLUSIONS: Doxapram has effect in increasing minute ventilation after propofol induction within first few minutes, but it cannot reverse respiratory depression during propofol induction pretreated with nalbuphine.

Effect of Doxapram on the Recovery from Vecuronium from Vecuronium of Mivacurium-induced Neuromuscular block in the Rabbit / 대한마취과학회지

Doxapram as a potent respiratory stimulant is one of attempts to solve respiratory problem and has been known to be effective for many years. But one study suggested that the presence of doxapram retarded neostigmine-induced antagonism of vecuronium effect. So we studied the effect of doxapram on the reverse of neuromuscular block when doxapram was injected with different dose. 60 rabbits were divided into 6 groups. Vecuronium was used in Group 1~3 and Mivacurium was used in Group 4~6 as a muscle relaxant. When the first twitch of TOF response reappeared from the complete block with a muscle relaxant (T1 onset), we administered neostigmine 0.05 mg/kg and saline 0.3 ml i.v. in Group 1, 4(VS, MS), neostigmine 0.05 mg/kg and doxapram 0.5 mg/kg i.v. in Group 2, 5(VDP1, MDP1), and neostigmine 0.05 mg/kg and doxapram 3 mg/kg i.v. in Group 3, 6(VDP2, MDP2). Two recovery time, from T1 onset to T1 25% and from T1 25% to T1 75%, and TR(ratio ; T4 twitch/T1 twitch) at T1 75% were measured. For the hemodynamic effect of doxapram, Blood pressure, heart rate and arrythmia were observed before and after doxapram injection too. The results are as follows. 1) Recovery time from T1 onset to T1 25% are 2'30"+/-0'29"(min'sec") in VS, 3'07"+/-0'4l"(minsec") in VDPl, 1'49"+/-0'17"(min'sec") in VDP2, 2'34"+/-0'17"(min'sec") in MS, 2'41"+/-0'25"(min'sec") in MDP1, 1'52"+/-0'39"(min'sec") in MDP2. 2) Recovery time from T1 25% to T1 75% are 4'58"+/-0'52"(min'sec") in VS, 6'10"+/-1'17"(min'sec") in VDP1, 3'38"+/-0'33"(min'sec") in VDP2, 4'38"+/-'0'57"(min'sec") in MS, 5'10"+/-0'55"(min'sec") in MDP1, 3'15"+/-0'38"(min'sec") in MDP2. 3) TR at T1 75% are 76.6+/-7.7% in VS, 82.4+/-3.4% in VDP1, 83.8+/-4.5% in VDP2, 81.4+/-2.3% in MS, 89.8+/-2.3% in MDP1, 89.8+/-1.5% in MDP2. 4) Heart rate, cardiac rhythm, systolic and diastolic pressure before and after doxapram injection were not significantly changed. In conclusion, simultaneous administration of neostigmine and low dose doxapram delayed recovery from the neuromuscular block, but high dose doxapram did not.

Comparison of Doses of Doxapram in the Treatment of Postanesthetic Shivering / 대한마취과학회지

Among the pharmacological methods treating postoperative shivering, there were no studies which compare the doses of doxapram. In this study, we have compared the effectiveness of doxapram in a placebo-controlled, double blind method. Sixty patients who shivered after operation under general anesthesia were examined. They were allocated randomly to receive normal saline(n=15), doxapram l mg/Kg(n=15), 1.5 mg/Kg(n=15) or 2 mg/Kg(n=15) from identical syringes intravenously. The investigator who gave the intravenous injection was unaware of the treatment received by the patient, and assessed the shivering. Both doxapram 1.5 mg/Kg and 2 mg/Kg were effective on shivering within 1~2 minutes after intravenous injection. In the saline group, all patients were still shivering 10 minutes after injection. In the doxapram 1 mg/Kg group, only two patients had stopped shivering by 6, 7 minutes after injection. In the doxapram 1.5 mg/Kg group, only three patients were shivering after injection. In the doxapram 2 mg/Kg group, only one patient was shivering after injection. We conclude that doxapram 1.5 mg/kg and 2 mg/kg were effective on postoperative shivering. And the results suggested that doxapram 2 mg/kg may be marginally superior to doxapram 1.5 mg/kg in this respect.

Effect of Doxapram on the Recovery from Vecuronium and Atracurium Neuromuscualr Block / 대한마취과학회지

The purpose of this study is to investigate the effects of doxapram on the rates of spontaneous and neostigmine-induced recovery from neuromuscular block with vecuronium and atracurium. Following intravenous injection of either vecuronium (40 patients) or atracurium (40 patients), recovery index (RI) was measured without administering either doxapram or neostigmine (Group 1), or after administration of a combination of neostigmine 40 ug/kg and doxapram 1 mg/kg (Group 2), neostigmine 40 ug/kg (Group 3) or doxapram 1 mg/kg (Group 4) when twitch tension returned to 25% block of train of four response, each of the four group had 10 patients. The results were such that RI was significantly prolonged after vecuronium in the presence of doxapram compared with Group 1 (13.5 min vs 8.2 min). There was no significant difference in the RI after atracurium in the presence of doxapram compared with Group 1 (7.0 min vs 7.1 min). There was rapid recovery which was significant when neostigmine was administered with or without doxapram (2.4 min vs 2.3 min respectively after vecuronium; 2.3 min vs 2.4 min respectively after atracurium). The authors conclude that administration of doxapram in situation where neuromuscular block with vecuronium is not adequately antagonized does not contribute to rapid recovery from neuromuscular block.

Effects of Doxapram HCI on the Hemodynamics after Isoflurane and Nitroglycerin Induced Hypotensive Anesthesia in Dogs / 대한마취과학회지

Isoflurane causes little myocardial depression, rapid onset and recovery during controlled hypotensive anesthesia. Nitroglycerin, vasodilating agent, has short plasma half-life and myocardial protective effect, is easy to cantrol, and has no direct toxic effect. Doxapram hydrochloride(doxapram Hcl), respiratory stimulant, has been found to be safe and significantly potent, but also has significant pressor effect when larger doses are administered. The purpose of this study was to evaluate the effects of doxapram on the hemodynamics after isoflurane and nitroglycerin-induced hypotensive anesthesia in dogs. Hemodynamic measurement including the value of left ventricular pressure, aortic pressure, pulmonary eapillary wedge pressure, pulmonary artery pressure, heart rate, cardiac output, maximal and minimal dP/dT were determined in 8 dogs before doxapram Hcl administration, Smin, 15min and 30min after doxapram Hcl administration. 1) Left ventricular pressure and aortic pressure increased at 5min and 15min after doxapram Hcl administration but did not change significantly at 30min compared to the preadministration values. 2) Pulmonary capillary wedge pressure and pulmonary artery pressure increased significantly at Smin and 15min, but did not change significantly 30min compared to the preadministration values. 3) Heart rate increased significantly at Smin, but did not change significantly at 15min and 30min compared to the preadministration value. 4) Cardiac output and body temperature did not change significantly at 5min, 15min compared to the preadministation values. 5) Maximal dP/dT increased signifieantly at Smin and 15min, but did not change at 30min compared to the preadministration value, minimal dP/dT increased significantly at 5min, but did not change at 15min and 30min compared to the preadministration value.

Respiratory Effects of Reversal of Morphine Induced Respiratory Depression by Doxapram / 대한마취과학회지

Postoperative respirative depression is a major factor limiting the use and safety of intraoperative narcotics. The need for an effective and safe narcotic antagonist to reverse this side effect without complication persists more than three decades of research. While narcotic induced respiratory depression can be reversed by appropriate, specific narcotic antagonist, it has not been possible to nulify the frespiratory depressant effects of narcotic without simultaneously nullifying the analgesic effects. Doxspram hydrochloride, respiratory stimulant, has been found to be significantly potent and selectively respirogenic. The present study undertakes to determine whether doxapram is ablereverse the respiratory depressnat effect of mrphine without mullifying the analgesic effects. In this study, 20 patients in 29 ASA class l patients given intravenous morphine, 0.5mg/kg, for elective surgery, produce postoperative respiratory depression. Inadequate spontaneous respiration at the end of anesthesia were treated with doxapram. The results were as follows: 1) Doxapram (mean 21.6mg) was able to reverse the respiratory depressant effect of morphine without nullifying the analgesic effect. 2) There was no hemodynamic alteration during reversal.